Project Summary/Abstract American Indian (AI) communities in the United States (US) are disproportionately affected by sexual and reproductive health disparities, compared to other populations, placing current and future generations of AI societies in jeopardy. Our study, ?Nen ?nkUmbi/EdaHiYedo (N/E - ?We are Here Now?)?, utilizes a culturally tailored ecological intervention in which the prevention of sexual-risk behaviors among AI youth that lead to STIs, HIV, HCV, and teen pregnancy are addressed. N/E takes place on the Fort Peck Reservation in northeastern Montana. N/E is a community-based participatory research sexual and reproductive health (SRH) intervention, constructed on Ecological Systems Theory. Based on Fort Peck tribal members' desire to implement a holistic SRH intervention for the tribes' youth, N/E includes: 1) A school-based SRH curriculum called Native Stand, designed to address individual-level factors that lead to risky behaviors; 2) a family-level curriculum called Native Voices, tailored to increase communication between adult family members and youth about SRH topics; 3) a cultural mentoring component at the community-level that pairs AI youth with adults and elders to discuss traditional AI beliefs and practices about SRH; and 4) a systems-level strategy to activate a multi-sectoral network of local youth servicing organizations to coordinate SRH services. The overarching aim of this proposal is to refine and tailor the components of N/E and evaluate its efficacy. N/E is a 5-year study involving 456 15- to 18-year-old AI youth and their parent/legal guardian. AIM 1 begins with a year of formative work to refine and tailor the components of N/E. Our community advisory board and the Fort Peck-based and MSU-based research team will design culturally appropriate adaptations for N/E's 4 levels. AIM 2 tests the efficacy of N/E using a cluster-randomized stepped-wedge design (SWD), in which the 5 high schools that Fort Peck youth attend are randomized into the intervention 1 at a time. N/E's primary outcome is increased condom use during sexual intercourse. Secondary outcomes are delayed onset of sexual intercourse, number of sex partners, frequency of sexual intercourse, pregnancy history, consistent use of birth control during sexual intercourse, and whether alcohol and/or other drugs are used during sexual intercourse. Tertiary outcomes are increased parent/legal guardian-child communication about SRH topics, increased understanding of cultural values related to traditional AI beliefs regarding SRH, and increased use of SRH services. Quantitative data collection includes: student surveys at baseline, 3, 9 and 12 months; parent/legal guardian surveys at baseline, 9 and 12 months. Qualitative data collection includes SRH service provider discussion groups at baseline and thereafter once a year over the 5-year study, with logs to track coordination and implementation at baseline and 3, 6, 9 and 12 months. AIM 3 will evaluate the fidelity and acceptability of N/E with focus groups, activity logs, and staff meeting notes and staff field notes.